For many years, I have suspected a connection between the two. After all, from the time we are 12 years old we are applying chemicals, such as aluminum, as well as others, directly under our arms which penetrate through the skin day after day for at least 60 years.  How can it not affect breast tissue?  I have read that there is a connection between the two, but after all, the antiperspirant business is not going away. We all need to do our research and become actively informed.